This application claims priority under U.S.C. § 119(a) on Patent Application No. 2004-318248 filed in Japan on Nov. 01, 2004, the entire contents of which are hereby incorporated by reference.
The present invention relates to a joint drive mechanism and a robot hand that can perform manual procedures by driving a plurality of finger mechanisms.
In this type of robot hands, in each joint portion a motor is provided, and the joint portions are directly rotated with the respective motors, bending and stretching the finger mechanisms. In such a robot hand mechanism, it is possible to rotate each joint of the finger mechanisms separately and a high degree of freedom of the finger mechanism can be achieved (see JP 2001-287182A, for example (hereinafter referred to as Patent Document 1)).
In other conventional apparatuses, the joint portions are linked by a wire and all finger mechanisms of the robot hand can be bent and stretched by pulling only this one wire. With such a robot hand mechanism, the number of drive sources can be reduced (see JP 2003-181787A for example (hereinafter referred to as Patent Document 2)).
However, when a motor serving as the drive source is installed in each joint part of the finger mechanisms in order to establish a high degree of freedom, as described in Patent Document 1, the finger mechanisms increase in size and a size equivalent to a human hand cannot be realized. Furthermore, since the front tips of the finger mechanisms are also equipped with a motor and are heavy, the motors at the base portion of the finger mechanisms require a large torque and the size of the robot hand further increases.
Moreover, in Patent Document 2, since the finger mechanism of the robot hand is bent and stretched by one motor, the hand has a complex configuration and since the degree of freedom is “1”, the robot hand cannot perform complex movements.
Accordingly, it was extremely difficult to realize a robot hand provided with a high degree of freedom and with a size equivalent to that of a human hand.
Therefore the present invention has been devised in light of these problems of the conventional art and it is an object thereof to provide a lightweight and compact joint drive mechanism, or more specifically, a robot hand with a high degree of freedom even and a size equivalent to that of a human hand, having a lightweight and compact joint drive mechanism.